Congratulations!
Now, to counteract all the scare stories people are telling you!
1. My sister was born when our mother was 39. She's an honors graduate of the University of Chicago, and she was 15th in her law school class, working days and going to school nights.
2. My friend Emily's first child was a breach. He was supposed to be a c-section, but he got there before the surgeon did. There's nothing the matter with him, except he plays ice hockey.

My grandfather was a fraternal twin. He was born in 1880. When the family's church had a bazaar, they had a display of the McCallister twins, two dolls labeled Edgar and Edna. That's how grandaddy got his name. His parents had been planning on naming him Edbert. Don't do that to your twins, and good luck!